:root {
  --background-color: #131018;
  --text-color: #fff;

  background-color: var(--background-color);
  font-family: ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  color: var(--text-color);
}

.wrapper {
  display: grid;
  grid-template-areas: 
    "header sidebar"
    "main sidebar";
  grid-template-rows: auto minmax(0, 1fr);
  grid-template-columns: minmax(0, 1fr) 300px;
}

header {
  grid-area: header;
  background-color: blue;
}

main {
  grid-area: main;
  background-color: green;
}

aside {
 grid-area: sidebar;
 background-color: orange;
}

p {
  margin: 0 0 12px 0;
}